Precipitation Nowcasting Algorithm

Algorithm for very-short-term precipitation forecasting based on the extrapolation of precipitation observations according to the estimated motion. It is composed of two different modules.

The first module, precipitation tracking, estimates the motion field with a given resolution based on the analysis of 2 or 3 consecutive radar maps, based on a modified version of COTREC.

The second module, extrapolation, produces precipitation nowcasts by linearly extrapolating the most recent radar precipitation map in time according to the retrieved motion field.

Two different versions of the nowcasting algorithm are available: a deterministic version, and a probabilistic version. The latter is an ensemble nowcasting approach that generates precipitation scenarios compatible with the most recent radar observations, and that respects the space-time structure of the precipitation field and its motion.